1. Field of the Invention
The invention relates to skid-steerable self-propelled vehicles, wherein the vehicle can be steered by slowing down or speeding up the wheels, tracks, or other ground reaction members on one side of the vehicle with respect to the ground reaction members on the other side.
2. Description of the Prior Art
In the most commonly encountered forms of skid-steering apparatus, brakes are applied selectively to the left-hand or right-hand ground reaction members. This has the disadvantage that it slows the vehicle and results in power losses. Proposals have also been made in Brown U.S. Pat. No. 2,408,507 and Remy et al U.S. Pat. No. 1,128,818 to employ two coupled differential gears to effect skid steering. However, these arrangements require a steering input drive, independent from the propulsion drive, to be applied continuously while turning the vehicle and the supply of this drive may be inconvenient or the drive may be difficult to control. Moreover, two distinct differential gear mechanisms have to be provided.